This Phase I/II multicenter trial is going to examine the safety of live- attenuated varicella vaccine in aymptomatic or mildly symptomatic HIV- infected children from 1-8 years of age with CD4 counts > 1000. Short and long-term systemic reactions along with clinical and immunological progression of HIV will be monitored. Cell mediated and humoral immunogenicity, persistence of immune response, response to booster immunizations (if needed), comparison of persistence of immunity of the vaccine vs wild type infection and virological progression of HIV will also be monitored.